Synthesis and bioactivities of poly(ethylene glycol)¯chitosan hybrids

Poly(ethylene glycol)¯chitosan hybrids of various molecular weights having different degree of substitution were synthesized, by reductive N-alkylation of chitosan with poly (ethylene glycol) aldehyde, to study their bioactivities. The influence of these chitosan derivatives on the reactive oxygen species generation from canine polymorphonuclear leukocyte cells was investigated in vitro by chemiluminescence response. Reactive oxygen species generation by the influence of poly(ethylene glycol)¯chitosan hybrids was decreased with the increase of degree of substitution. The reduction of interaction of poly(ethylene glycol)¯chitosan hybrids with polymorphonuclear leukocyte cells might be caused by the decrease of amino group in chitosan main chain and increase of the steric hindrance by poly(ethylene glycol) chain. The influence of the poly(ethylene glycol)¯chitosan hybrids on complement component C3 activation was investigated by single radial immunodiffusion method. Influence on complement component C3 activation by poly(ethylene glycol)¯chitosan hybrids was almost same as chitosan.